Effectiveness of a Multicomponent Intervention to Promote Physical Activity Levels During the School Day (MOVESCHOOL)

Physical activity and sedentary time will be measured through accelerometry (Actigraph GT3X+, Inc., Pensacola, FL, USA).

The 20-metres shuttle run test will be used to assess cardiorespiratory fitness. Participants will run the 20-metre distance to the rhythm of a recording. The initial speed is 8.5 km/h and will be increased by 0.5 km/h per section. The race will end when the participant stops due to fatigue or when he/she fails to cross the marked lines to the rhythm of the acoustic signals on two consecutive occasions. The last stage or half stage completed by the competitor will be scored.

The hand grip test will be used to assess musculoskeletal capacity of upper body. The test shall be performed twice with each hand alternately. The maximum score of each hand in kilograms shall be recorded and the mean value between them shall be calculated.

Standing broad jump shall be used to assess the musculoskeletal capacity of the lower limbs. The participant shall stand behind a line with feet shoulder width apart. The participant is then asked to jump forward as far as possible with both feet. If he/she rests his/her hands or lifts his/her feet off the ground when landing, the test is invalid. The test shall be performed twice, and the best score recorded in centimetres.

Weight and height will be combined to report BMI in kg/m^2.

Waist circumference shall be measured as a body composition variable with a non-elastic tape placed in the frontal plane at the midpoint between the upper iliac spine and the costal border at the mid-axillary line. The measurement shall be taken twice and the mean of the two measurements shall be recorded.

Self-reported screen time will be assessed using the Youth Leisure-time Sedentary Behaviour Questionnaire (YLSBQ). Five questions will be selected from the original questionnaire and participants will be asked to answer them by selecting the amount of time they spend per day on each question, ranging from 0 minutes to 5 or more hours.

The International Fitness Scale will be used for the assessment of subjective physical fitness. Participants will be asked to rate each of the fitness components on a 5-point Likert-type scale ranging from: "very poor" (1); "poor" (2); "fair" (3); "good" (4) and "very good".

The EuroQol five dimensions three levels will be used to assessment of health status (EQ-5D-3L).This questionnaire is composed of the dimensions of: (i) mobility; (ii) self-care; (iii) usual activities; (iv) pain/discomfort and (v) anxiety/depression. The three levels that participants should mark a Likert-type scale correspond to (i) no problem; (ii) some problems; (iii) many problem.

Self-perceived health will be measured through the classic self-reported health item, where participants will have to classify their health among the following options: "excellent" (5); "very good" (4); "good" (3); "fair" (2) and "poor" (1).

The engagement scale (UWES-S-9) will be used to evaluate school engagement. The UWES-S-9 is composed of nine items that reflect the three dimensions of engagement: (i) vigor; (ii) absorption; and (iii) dedication, each dimension is represented by three items that will be evaluated through a Likert-type scale, ranging from "never" (0 points) to "always" (6 points).

Learning perception in mathematics and in general studies will be assessed by means of a questionnaire consisting of eight items. Items 1- 4 will assess the "perceived learning" dimension and items 5-8 will measure the "satisfaction with learning" dimension. All items will be scored according to a five-point Likert scale, where "1" is (strongly disagree) and "5" is (strongly agree).

Academic performance will be evaluated through the marks reported by the schools before and after the intervention.

Inhibition will be evaluated through the Flanker task protocol, part of the NIH Examiner programme. This is a computerised programme where the subject answers the tests individually. The algorithm provided by the program, ranging from 0 to 10, which includes accuracy and reaction time, will be recorded.

Cognitive flexibility will be evaluated through the Shifting task protocol, part of the NIH Examiner programme. This is a computerised programme where the subject answers the tests individually. The algorithm provided by the program, ranging from 0 to 10, which includes accuracy and reaction time, will be recorded.

Working memory will be evaluated through the N-Back protocol, part of the NIH Examiner programme. This is a computerised programme where the subject answers the tests individually. The algorithm provided by the program, ranging from 0 to 10, which includes accuracy and reaction time, will be recorded.

Novelty will be assessed through the Novelty Need Satisfaction Scale. Five of the 19 questions that make up the original scale will be selected and participants will be asked to answer them on a Likert-type scale where 1 = "strongly disagree" and 5 = "strongly agree".

School climate will be assessed using the students' perception of school climate scale (PACE-33). Fifteen items will be evaluated. All items will be scored according to a five-point Likert scale, where "1" is (strongly disagree) and "5" is (strongly agree).

Enjoyment and boredom will be assessed using the Spanish version of The Sport Satisfaction Instrument. This scale is composed of eight items. Participants will have to rate their degree of agreement with the items referring to fun or boredom on a five-point Likert-type scale, ranging from 1 (strongly disagree) to 5 (strongly agree).

Adherence to the Mediterranean diet will be measured using the updated version 2.0 of the KIDMED questionnaire.

Sociodemographic characteristics will be measured through the Spanish-adapted version III of The Family Affluence Scale. This scale is composed of six questions . Each question is scored on a categorical scale, and the sum of the scores from the six items result in an aggregate index ranging from 0 to 13.

Perception about the suitability and the development of the intervention program (perceptions, barriers, points to improve, strengths...) a semi-structured interview will be conducted with the teachers involved in the intervention.

A discussion group will be developed for each of the proposed interventions with a subsample of students, in order to obtain information on the suitability and development of the intervention programme (perceptions, barriers, areas for improvement, strengths, etc.).